Oil sealing unit in rotary piston engine

ABSTRACT

An annular sealing member and a wavy spring are mounted in an oil sealing unit mounting groove formed on each side face of a rotor. The annular sealing member has a recess or recesses formed in the contacting surface with the wavy spring for receiving a crest or crests of said wavy spring, whereby said annular sealing member is secured to said wavy spring.

United States Patent Inventor Yoshitugu Hamada Nagahama-Shi, Japan Appl. No. 868,849

Filed Oct. 23, 1969 Patented Apr. 20, 1971 Assignee Yanmar Diesel Engine Co., Ltd.

Osaka, Japan Priority Dec. 11, 1968 Japan 1075 13/ 68 OIL SEALING UNIT IN ROTARY PISTON ENGINE 1 Claim, 4 Drawing Figs.

US. Cl 418/144, 277/81, 418/61 Int. Cl F01c 19/00, FOlc 1/02 Field of Search 418/61, 144; 277/81, 83

[56] References Cited UNITED STATES PATENTS 3,142,440 7/1964 Schagg 418/61 3,180,563 4/1965 Jones et al. 418/61 3,300,127 1 1967 Yamamoto et al. 418/61 3,321,128 5/1967 Fezer et al. 418/61 Primary ExaminerCarlton R. Croyle Assistant Examiner-Wilbur J. Goodlin AtmmeyStevens, Davis, Miller & Mosher ABSTRACT: An annular sealing member and a wavy spring are mounted in an oil sealing unit mounting groove formed on each side face of a rotor. The annular sealing member has a recess or recesses formed in the contacting surface with the wavy spring for receiving a crest or crests of said wavy spring, whereby said annular sealing member is secured to said wavy spring.

OIL SEALING UNIT IN ROTARY PISTON ENGINE BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil sealing unit adapted to be incorporated in a piston (rotor) of a rotary piston engine comprising a cylindrical housing, a side housing to close each side of said cylindrical housing and the piston disposed in said cylindrical housing for rotation therein.

2. Description of the Prior Art An oil sealing unit to be used in a rotary piston engine, which consists of an annular sealing member, a rubber ring to be mounted in said annular sealing member and a wavy spring for pressing said annular sealing member against the adjoining side housing, is already known (see Japanese Utility Model Publication No. 6,321/68).

In this prior-art oil sealing unit, the annular sealing member rotates relative to the rotor and the wavy spring during rotation of said rotor, so that said wavy spring is worn out by said annular sealing member and finally breakage of the spring results.

SUMMARY OF THE INVENTION The present inventors have found that the relative rotation of the annular sealing member with respect to the rotor can be prevented by securing said annular sealing member to the wavy spring. According to the present invention, the annular sealing member is secured to the wavy spring by engaging the crests of the wavy spring in corresponding recesses formed in the surface of that side of the annular sealing member which is in contact with said wavy spring, whereby the above-described drawback can be eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in detail hereunder with reference to the accompanying drawings, in which:

FIG. 1 is a sectional view of a conventional oil sealing unit in a rotary piston engine;

FIG. 2 is a developed sectional view taken on the line A-A of FIG. 1;

FIG. 3 is a diagram showing a force imposed on the oil sealing unit; and

FIG. 4 is a view, similar to FIG. I, of the oil sealing unit according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, reference numeral 1 designates a cylindrical housing, 3 a side housing closing each side of said cylindrical housing 1 and 5 a rotor disposed in the cavity, defined by said cylindrical housing and said side housings, for rotation therein. An oil is supplied into a cavity 7 interior of the rotor 5 for cooling said rotor. Grooves 8a, 8b are formed in each side face of the rotor, in each of which are disposed an annular sealing member 9a or 9b, a rubber ring 11a or [lb and a wavy spring 13a or 13b. The annular sealing member is pressed against the inside face of the adjoining side housing by the wavy spring to scrape into the cavity of the rotor the oil attached to the inside face of said housing.

FIG. shows the manner in which the wavy spring 13a engages the annular sealing member 9a.

FIG. 3 is a side view of the rotor. Of the two sets of inner and outer sealing units shown in FIG. 3, theouter sealing unit only is shown by the wavy spring, with the annular sealing member and the rubber ring removed, for convenience in explanation. Reference symbol 0a designates the instantaneous center of the inertia force created in the component parts of the sealing unit incorporated in the rotor. Namely. radial inertia forces acting in radial directions with respect to the instantaneous center 0a are imposed on the wavy spring 13a, incident to rotation of the rotor. Such inertia forces at the representative positions of the wavy spring are indicated by P P P P respectivel The wav spring 13a has an abut mg 10ml l a and is expan ed outwar ly under the influence of said inertia forces, to be strongly pressed against the wall of the groove 8a formed in the rotor.

Reference symbol O designates the instantaneous center of velocity of the rotor 5 and the component parts of the sealing units incorporated in said rotor. As the rotor is rotated in the direction of arrow, the annular sealing member 9b slides on the inside face of the adjoining side housing (indicated by numeral 3 in FIG. I), so that said annular sealing member is subjected to a frictional force acting thereon in a direction opposite to the rotating direction thereof and concentric with the instantaneous center Oy- Such frictional forces at the representative positions of the scaling member are indicated by Q Q and Q;,. It is the moment of this frictional force which causes the relative rotation of the annular sealing member with respect to the rotor. Furthermore, the annular sealing member is in contact with the wavy spring (indicated by numeral in FIG. 2) and a frictional force occurs at each point of contact which urges said wavy spring to rotate along with said sealing member. However, the rotational force caused by the frictional force is not so large as to cause the wavy spring, in pressure engagement with the wall of the sealing unit mounting groove under the inertia force, to rotate along with the annular sealing member relative to the rotor. Consequently, the wavy spring secured to the rotor and the annular sealing member making a relative movement with respect to the rotor slide relative to each other and hence the spring is worn out by said sealing member.

If the annular sealing member is fixed to the wavy spring, it is after all secured to the rotor, because the wavy spring is securely held in the sealing unit mounting groove under inertia force as stated previously.

According to the present invention, recesses 16 are formed in the inner surface of the annular sealing member 9a and the crests of the wavy spring 13a are securely fitted in the corresponding recesses 16, whereby the annular sealing member is secured to the wavy spring and hence secured to the rotor. Such recess may be formed in each annular sealing member at a plurality of locations.

I claim:

I. An oil sealing unit for use in a rotary piston engine comprising a cylindrical housing, a side housing closing each side of said cylindrical housing and a piston (rotor) disposed in the cavity defined by said cylindrical housing and said side housings for rotation therein and incorporating said oil sealing unit, said oil sealing unit comprising an annular sealing member and a wavy spring, said annular sealing member being formed with at least one recess in the contacting surface with said wavy spring for engagement with said wavy spring. 

1. An oil sealing unit for use in a rotary piston engine comprising a cylindrical housing, a side housing closing each side of said cylindrical housing and a piston (rotor) disposed in the cavity defined by said cylindrical housing and said side housings for rotation therein and incorporating said oil sealing unit, said oil sealing unit comprising an annular sealing member and a wavy spring, said annular sealing member being formed with at least one recess in the contacting surface with said wavy spring for engagement with said wavy spring. 